At present, the research on the sintered porous material mainly focuses on several aspects of the optimization of preparation processes, the exploration of pore-forming mechanisms, the improvement of material properties and the extension of application ranges. Among them, as for the pore-forming mechanisms, the pore-forming means applied to the method for preparing the sintered porous material mainly comprise: firstly, forming pores by chemical reactions, the mechanism of which is on the basis of the partial diffusion effect caused by the larger differences in the intrinsic diffusion coefficients of different elements, thereby resulting in generating the Kirkendall pores in the material; secondly, forming pores by the physical accumulation of raw material particles; finally, forming pores by the escape of additives. The selection and combination of the pore-forming means described above can inevitably cause the direct effect on the pore structure of the porous material. The pore structure of the porous material can further determine the properties of the porous material. Thus, the sintered porous materials generated on the basis of different pore-forming means always have different pore structures and service performances, and these porous materials can be identified and characterized more clearly by understanding and measuring the pore structures and the service performances. At present, in order to adequately characterize the porous materials, it is usually adopted in the art of: 1) compositions and content of the raw material; 2) pore structures, mainly comprising porosity, pore diameter and so on; 3) material property parameters, comprising permeability, mechanical strength and chemical stability, wherein, the permeability is usually measured by a fluid permeation method, the mechanical strength is usually represented by tensile strength, and the chemical stability is mainly represented by acid resistance and/or alkali resistance.
A Fe—Al intermetallic compound porous material is a sintered inorganic porous material between high temperature alloys and ceramics. It is bonded together by metallic bonds and covalent bonds, and has common advantages of both metal materials and ceramic materials; thus, the Fe—Al intermetallic compound porous material has a broad application prospect as a filter material (in particular, as a high temperature gas filter material). It is generally acknowledged that the Fe—Al intermetallic compound porous material has excellent properties; however, for some special application fields, the high temperature oxidation resistance property and the strong alkali corrosion resistance of the Fe—Al intermetallic compound porous material still need to be improved. Before the filing date of the present application, the sintered Fe—Al based alloy porous material, which can improve the high temperature oxidation resistance property and the strong alkali corrosion resistance property of the Fe—Al intermetallic compound porous material, and in the meantime also can improve the pore structure of the material additionally and achieve good comprehensive service performances, has not been discovered.